The aim of this study was to identify the characteristics of an a FeOOH based composite for the removal of hydrogen sulfide in room temperature gas streams. alpha-FeOOH was supported on commercial-activated carbon powder to avoid the agglomeration problem of composite fabrication. a-FeOOH was prepared by using FeCl3 solution (as an Fe precursor) and NH4HCO3 (as a pH control). The formation of a-FeOOH was confirmed by observing alpha-Fe2O3 under the hydrothermal condition. The results of the experiment indicate that the activated carbon powder functioned effectively as the support material of the composite, providing a large active site on the surface of the composite, preventing the agglomeration of precipitate particles of FeOOH, and then allowing high breakthrough capacity (0.171 g H2S/g composite) compared to that of alpha-FeOOH alone (0.046 g H2S/g alpha-FeOOH). The textural analyses showed that the composite of the alpha-FeOOH and activated carbon powder had a mesoporous structure with a BET surface area of 500 m(2)/g, while the surface area was 188 m(2)/g for alpha-FeOOH alone. This study established that the synthesized material can be used as a heterogeneous adsorbent for the effective removal of hydrogen sulfide from gas streams.